The present invention relates generally to monitoring the administration of enteral nutritional fluids to a feeding tube which has been implanted in the body of a patient.
Certain patients are unable to take food and/or medications transorally due to an inability to swallow. Such an inability to swallow may be due to a variety of reasons, such as esophageal cancer, neurological impairment and the like. Although the intravenous administration of food and/or medications to such patients may be a viable short-term approach, it is not well-suited for the long-term. Accordingly, the most common approach to the long-term feeding of such patients involves gastrostomy, i.e., the creation of a feeding tract or stoma between the stomach and the upper abdominal wall. (A less common approach involves jejunostomy, i.e., the creating of a feeding tract or stoma leading into the patient's jejunum.) Feeding is then typically performed by administering food through a catheter or feeding tube that has been inserted into the feeding tract, with the distal end of the feeding tube extending into the stomach and being retained therein by an internal anchor or bolster and the proximal end of the feeding tube extending through the abdominal wall.
Although gastrostomies were first performed surgically, most gastrostomies are now performed using percutaneous endoscopy and result in the implantation of a catheter/bolster assembly (also commonly referred to as a percutaneous endoscopic gastrostomy (PEG) device) in the patient. Two of the more common techniques for implanting a PEG device in a patient are “the push method” (also known as “the Sacks-Vine method”) and “the pull method” (also known as “the Gauderer-Ponsky method”).
After a PEG device is implanted, the proximal portion of the implanted gastrostomy feeding tube is typically severed to reduce the externally-extending portion of the tube to a desired length (typically about 4-6 inches). An external bolster is then secured to the remaining exposed length of the implanted tube to prevent the retraction of the tube into the patient's stomach.
A “Y-port” adaptor is commonly attached to the proximal end of the implanted feeding tube. The Y-port adaptor is typically constructed as a unitary, tubular member made of silicone or the like which includes an unbranched distal end and a branched proximal end. The unbranched distal end of the Y-port adaptor is typically connected to the proximal end of the implanted feeding tube using a tubular connector. The branched proximal end of the Y-port adaptor is typically shaped to include a pair of lumens, a larger diameter lumen and a smaller diameter lumen. The larger diameter lumen is adapted to receive the dispensing tip of a syringe or feeding set adapter of the type through which food is typically dispensed. The smaller diameter lumen is adapted to receive the dispensing tip of a syringe or feeding set adapter of the type through which medication is typically dispensed.
The Y-port adaptor also typically includes a pair of tethered plugs, the plugs being used to ‘cap’ the lumens when the lumens are not in use (the Y-port adaptor typically remaining secured at all times to the proximal end of the feeding tube). In this manner, the plugs prevent undesired materials from entering the patient through the Y-port adaptor. At the same time, the plugs are also intended to prevent the escape of the patient's stomach contents through the Y-port adaptor.
Enteral nutritional fluids are typically administered to a patient using either a bolus feeding technique or a drip feeding technique.
In the bolus feeding technique, enteral nutritional fluids are manually administered to the patient using a conventional syringe. Specifically, the dispensing tip of a syringe which contains the required nutritional fluids is inserted into the larger diameter lumen of the Y-port. The nutritional fluid is then administered to the patient by applying a manual dispensing force to the plunger of the syringe.
Although effective in administering nutritional fluids to a patient, the bolus feeding technique suffers from a few notable drawbacks.
As a first drawback, the bolus feeding technique provides the fluid administering party with limited control of the rate in which the fluid is dispensed into the patient. In fact, the rate of fluid administration is directly dependent upon the injection force applied to the syringe plunger by the fluid administering party. As a consequence, it has been found that nutritional fluids administered using the bolus feeding technique are often delivered to a patient at an unacceptably fast rate. The administration of enteral nutritional fluids at such a fast rate can undesirably cause the patient to experience, inter alia, abdominal pain, gas, and/or bloating.
As a second drawback, the bolus feeding technique requires continuous human intervention, thereby rendering the bolus technique considerably labor intensive. Specifically, the person responsible for the administration of the fluid (e.g., a nurse, a trained professional, or even the patient himself) is required to manually dispense all of the syringe contents by depressing the syringe plunger. This can be time-consuming as the bolus administration of 200 cc of nutritional fluids can often take as long as 30 minutes.
Due to the aforementioned drawbacks associated with the bolus feeding technique, it has been found that drip feeding techniques for administering enteral nutritional fluids into the body of a patient are typically preferred.
In the drip feeding technique, enteral nutritional fluids are typically packaged within a deformable supply pouch. A fluid delivery set, also referred to herein as a feeding set, serves a conduit through which the fluids can travel from the supply pouch and into a desired lumen of the Y-port. The fluid delivery set commonly includes a drip chamber having an inlet which is adapted to receive, directly or through a connecting piece of flexible tubing, nutritional fluids from the supply pouch. The outlet of the drip chamber is connected to an elastically flexible tubing, such as a silicone rubber tube, or interconnected lengths thereof, which is in turn inserted into the desired lumen of the Y-port via an adaptor.
The fluid which collects within the feeding set drip chamber is typically transported to the Y-port either through the use of natural gravitational forces (i.e., disposing the supply pouch at a height above the Y-port) or through the use of an enteral feeding pump.
A rotary peristaltic pump is one well known type of enteral feeding pump. A rotary peristaltic pump commonly includes a motor driven peristaltic rotor mounted on a shaft which extends out through the front wall of the pump housing. The peristaltic rotor carries an array of equidistantly spaced rollers along its outer periphery. The elastically flexible tubing which connects the outlet of the drip chamber to the Y-port is wrapped around the rotor in tension against the plurality of rollers. Accordingly, as the rotor is rotated, the rollers squeeze the flexible tubing so as to force a predetermined amount of the fluid through the flexible tubing by means of the squeezing action. The pump is typically provided with an electronic control circuit for regulating the operation of the rotor which, in turn, controls the rate and schedule of fluid administration into the body of the patient. Based on the operation of the rotor, the control circuit can calculate the amount of fluid dispensed to the Y-port (and, in turn, to the patient) over one or more feeding periods.
The use of an enteral feeding pump to transport enteral nutritional fluids from the feeding set drip chamber to the implanted feeding tube provides a number of significant advantages over the use of natural gravitational forces to transport enteral nutritional fluids from the feeding set drip chamber to the implanted feeding tube.
As a first advantage, the utilization of an enteral feeding pump allows for the metering of a specified amount of nutritional fluid to the patient. In this capacity, an enteral feeding pump can ensure that a patient ultimately receives the proper amount of nutritional fluid, which is highly desirable. In fact, once the pump determines that the proper amount of fluid has been delivered to the patient, the feeding pump will terminate further rotation of the rotor. In addition, if the proper amount of fluid is not delivered to the patient over a specified period of time, the pump can be programmed to activate an alarm which is electrically connected to the pump control circuit. To the contrary, gravitational feeding techniques are only capable of delivering a non-adjustable amount of fluid to the patient (i.e., the amount of fluid contained within the supply pouch).
As a second advantage, the utilization of an enteral feeding pump allows for the rate of fluid administration to be adjusted (typically between 5 ml/hr to 75 ml/hr) as deemed necessary to maximize the effectiveness in which the patient absorbs the nutrients in the fluid. To the contrary, gravitational feeding techniques are more limited in their maximum fluid feed rates as they are dependent upon the fluid level within the pouch and the height of the pouch relative to the implanted feeding tube.
As a third advantage, the utilization of an enteral feeding pump allows for intermittent feeding at user-specified feeding cycles. Specifically, the control circuit of the feeding pump can be programmed to monitor the time which has elapsed since the last feeding period and, in turn, re-commence the feeding process once the elapsed time reaches a pre-defined level. To the contrary, gravitational feeding techniques only allow for a single, uninterrupted feeding period.
Although well-known and widely used in the art, one problem is commonly associated with the use of enteral feeding pumps. Specifically, enteral feeding pumps of the type described above are commonly shared amongst a plurality of patients. For example, in certain situations (e.g., a hospital or nursing home), a single pump can be used to routinely administer enteral nutritional fluids for a large group of patients who have distinct feeding requirements. Because a single pump is often used to dispense fluids for multiple patients, it is essential that the pump be constantly re-programmed to match the precise fluid administration requirements of a particular patient. If the feeding pump is not properly re-programmed in accordance to the precise fluid administration requirements of a particular patient, said patient becomes susceptible to improper feedings, which is highly undesirable.